As part of the completion operations for a water well it is normal practice to place a cylindrical screen or perforated pipe in the well bore through the water bearing strata. In order to prevent clogging of the screen or perforations by fine dirt and sand particles it is desireable to pack the annular space between the cylindrical screen and the well bore with coarse sand or gravel which will act as a barrier or filter against influx of the fine particles and other solid contaminants in the water bearing strata.
It is also desireable, after placement and packing of the screen, to place a well seal or packing seal in the well bore to retain the packing material. The sealing operation is commonly followed by a cleaning operation to remove dirty, contaminated water from the well bore prior to placing a production pump in the well, in order to prevent initial damage to the pump from abrasive materials. The cleaning operation typically consists of introducing an open-ended pipe into the well and introducing compressed air into the well bore through the pipe to force the water from the well through the annular space between the well casing and the pipe.
Each of these operations has, in the past, required a separate run of a string of pipe down the well bore, a time consuming and laborious operation. The present invention overcomes this disadvantage by allowing screen placement, packing, sealing, and cleaning to be performed with a single run down the bore. The present invention also improves the efficiency of the packing and air jet cleaning operations.